1. Technical Field
The present invention relates to a light source unit, and more particularly, to a light source unit having a collimating lens.
2. Background Art
JP-3070996-B1 (JP-H05-088061-A) and JP-4132598-B1 (JP-2001-228419-A), for example, disclose a light source unit for use in an image forming apparatus or the like that has a semiconductor laser and a collimating lens arranged on a light path of beams of light emitted from the semiconductor laser.
In such a configuration, the directionality (optical axiality) of the emitted beams of light and parallelism (collimation) are important.
For this reason, at least one of the semiconductor laser and the collimating lens are adjusted about three axes mutually perpendicular to each other to obtain a desirable position relative to the luminous point of the semiconductor laser and the collimating lens. This precision positioning requires accuracy to within 1 micrometer or less.
However, conventionally, the effect of an external impact on the light source unit has not been considered in the design thereof.
In particular, an impact applied from a direction parallel to the optical axis of the collimating lens possibly displaces the relative positions of the luminous point of the semiconductor laser and the collimating lens.